Usefulness of a small-caliber tip transparent hood in endoscopic submucosal dissection for pharyngeal cancer

Endoscopic submucosal dissection (ESD) for superficial pharyngeal cancer is becoming an established minimally invasive treatment with favorable short- and long-term outcomes [1] [2] [3]. In recent years, a small-caliber tip transparent hood (CAST hood; TOP, Tokyo, Japan) has been useful in cases involving severe fibrosis and pocket creation [4].

A 69-year-old man with a history of ESD for esophageal cancer was referred to our hospital for an erythematous lesion on the posterior wall of the hypopharynx detected by upper gastrointestinal endoscopy during a routine examination ([Fig. 1] a–d). A tissue biopsy confirmed the diagnosis of squamous cell carcinoma, and we performed ESD ([Video 1]) under general anesthesia using a GIF-H290T (Olympus, Tokyo, Japan) and DualKnife J (KD-655Q; Olympus). An incision was made on the anal side using a transparent distal attachment hood (D-201-11804; Olympus). A circumferential incision was then made, and the distal attachment was changed to the CAST hood. The lesion was resected en bloc within 24 minutes without the use of traction devices and any adverse events ([Fig. 2] a–i). Histopathology confirmed R0 resection of a 14 × 12-mm large well-differentiated squamous cell carcinoma that had invaded the subepithelium with a tumor thickness of 350 μm ([Fig. 3] a, b).

Fig. 1 Pretreatment endoscopic evaluation. a, b An erythematous 0-IIb lesion with partial melanosis was seen at the posterior wall of the hypopharynx. The distal side of the lesion was not fully visible due to the postcricoid region riding over it. c, d Magnified endoscopy with narrow-band imaging showing a brownish lesion with dilated and irregularly aligned intrapapillary capillary loops, suggesting that tumor invasion was limited to the subepithelial layer.

Fig. 2 Endoscopic procedure. a, b A curved rigid laryngoscope was used to expand the larynx to visualize the entire lesion. c Markings were made 5 mm outside the lesion while lifting the postcricoid region with laryngeal forceps to ensure visibility. d Lugol’s iodine staining shows a Lugol-voiding area consistent with the brownish area of narrow-band imaging. e An incision was made from the anal side, followed by a circumferential incision. f, g The small-caliber tip transparent hood facilitated visualization and dissection of the submucosal layer through a shallow incision even in a confined space, making it easier to get under the specimen. h, i The lesion was resected en bloc without any adverse events.

Fig. 3 Histological examination findings of the resected specimen. a, b Photomicrographs ([a] × 40, [b] × 200) of the lesion with hematoxylin and eosin staining. Tumor cells infiltrating the subepithelial layer without lymphovascular invasion.

Successful endoscopic submucosal dissection of pharyngeal cancer using a small-caliber tip transparent hood.Video 1

ESD for pharyngeal carcinoma can be difficult because of the limited working space. While the ultrathin endoscope has highly flexible operability [5], it does not have a water jet function, and suction cannot be used during treatment. The CAST hood is a transparent hood with a tip diameter of 4 mm, making it easier to maintain visibility and perform fine manipulation in confined spaces. The gradual increase in diameter from the tip allows natural traction, minimizing the amount of glycerol injected and the risk of laryngeal edema. These findings suggest that the CAST hood is particularly suitable for the endoscopic treatment of pharyngeal cancer lesions.

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Conflict of Interest

The authors declare that they have no conflict of interest.

• References

• 1 Iizuka T, Kikuchi D, Hoteya S. et al. Endoscopic submucosal dissection for treatment of mesopharyngeal and hypopharyngeal carcinomas. Endoscopy 2009; 41: 113-117
• 2 Shimizu Y, Yamamoto J, Kato M. et al. Endoscopic submucosal dissection for treatment of early stage hypopharyngeal carcinoma. Gastrointest Endosc 2006; 64: 255-259
• 3 Iizuka T, Kikuchi D, Suzuki Y. et al. Clinical relevance of endoscopic treatment for superficial pharyngeal cancer: feasibility of techniques corresponding to each location and long-term outcomes. Gastrointest Endosc 2021; 93: 818-827
• 4 Kikuchi D, Tanaka M, Suzuki Y. et al. Endoscopic submucosal dissection for superficial pharyngeal carcinoma using transnasal endoscope. VideoGIE 2021; 6: 67-70
• 5 Nomura T, Sugimoto S, Oyamada J. et al. GI endoscopic submucosal dissection using a calibrated, small-caliber-tip, transparent hood for lesions with fibrosis. VideoGIE 2021; 6: 301-304

Publication History

Article published online:
19 September 2024